Improvement in lightning-rods



parts is clearly shown in Fig. 2.

UNITED STATES PATENT GFEICE.

ISAAC JOHNSON, OF CHICAGO, ILLINOIS.

IMPROVEMENT IN LIGHTNING-RODS.

Specification forming part of Letters Patent No. 170,377, dated November23, 1875; application tiled January 19, 1875.

ling, and Fig. 3 a like representation of thecoupling detached.

Like letters ot' reference indicate like parts.

My object is to provide improved means for'the purpose of couplingtogether the sections oi' tubular lightning-rods; and to that end myinvention consists of a hollow and indented coupling-piece, open at bothends, and arranged substantially as hereinafter described with relationto correspondingly-indented sections ot' the rod.

v In the drawing, A and A represent sections of tubular lightning-rods.Bis the coupling-piece. This piece is made tubular, and is of such asize and form that it may be easily inserted into the ends of thesections of the rod, and yet lit nicely therein. a c are annular groovescut or sunken into the part B.

In order to couple together the sections ol' tubular rods by means ofthepart B, I insert the latter into one end of a section until one of thegrooves on the coupling is covered by the rod. I then swage the rod intothe groove thus covered, employing for this purpose any suitable tool.This part of the operation is shown in Fig. l, e representing the groovethus made in rod. In order to determine where the swagingtool should beapplied to the rod, both the coupling-piece and rod may be so markedthat when the edge or end of the section reaches the mark on the couplerthe mark on the section will be directly over the groove into which therod is to be swaged. The proper position of the One end of each sectionis thus provided with a couplingpiece, and the sections may be shippedin this x the manner described may be easily and rap- .Mp

idly performed, and with slight expense. The

rod is not cut or weakened at any point, butl is rendered stiti'est andstrongest at the joints,

and the sections are firmly united. The rod is also of a uniform size.

It is frequently desirable to introduce solid rods within the tubularsections, the solid rods being continued past the `joints of the tubularsections. By employing the tubular pieces B B, in the manner described,these solid rods may be readily introduced, and the water may also passfreely through the tubuf lar part of the rod. S,

I am aware that solid coupling-pieces, hav ing their outer surfacescorrugated to admit` ot' the passage ot' water along the interior oil`the rod, have heretofore been employed for the purpose of uniting thesections of tubular rods, the couplingpieces and sections beingindented, and arranged substantially as described with relation to eachother, and I do not here claim such; but,

Having thus described my invention, what I claim as new, and desiretosecure by Letters Patent, is-

A tubular lightning-rod made in sections, and indented, substantially asdescribed, in combination with the hollow and correspondingly-indentedcoupling-pieces B B, open at both ends, and arranged as shown withrelation to the sections, substantially as and for the purposes setforth. Y

ISAAC JOHNSON. Witnesses:

N. O. GRIDLEY, F. F. WARNER.

